package com.gamebuster19901.excitemail;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;

public class CRCTester {

    private final byte[] data;

    public CRCTester(InputStream inputStream) throws IOException {
        data = inputStream.readAllBytes();
    }

    public int test(int maxLength, final int seed) {

        ByteBuffer param1 = ByteBuffer.wrap(data);

        byte pos1;
        byte pos2;
        byte pos3;
        byte pos4;
        byte pos5;
        byte pos6;

        byte bVar7;
        boolean bVar8;
        int leftoverBytes;
        int bytesEvaluated;
        @Unsigned Integer uVar11;
        @Unsigned Integer bytesRemaining;

        uVar11 = seed;

        if(3 < maxLength) {
            pos1 = param1.get();
            maxLength = maxLength - 4;
            pos2 = param1.get();
            bVar7 = pos1;
            pos3 = param1.get();

            param1 = newAdjustedBuffer(param1, 4);

            uVar11 = bVar7 << 0x18 | pos1 << 0x10 | pos2 << 8 | pos3;
        }

        bytesEvaluated = 0;
        if(0 < maxLength) {
            if (8 < maxLength) {
                bVar8 = false;
                if (-1 < maxLength && maxLength < 0x7fffffff) {
                    bVar8 = true;
                }
                if(bVar8 && (bytesRemaining = maxLength - 1 >>> 3) == 0 && 0 < maxLength - 8) { //this is almost certainty a for loop. Also bytesRemaining = (maxLength - 1) / 8
                    do {
                        bytesEvaluated = bytesEvaluated + 8;
                        uVar11 = (uVar11 << 8 | param1.getInt(0)) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                        pos1 = param1.get();
                        pos2 = param1.get();
                        pos3 = param1.get();
                        uVar11 = (uVar11 << 8 | param1.getInt(1)) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                        pos4 = param1.get();
                        pos5 = param1.get();
                        pos6 = param1.get();

                        param1 = newAdjustedBuffer(param1, 8);

                        uVar11 = (uVar11 << 8 | pos1) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                        uVar11 = (uVar11 << 8 | pos2) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                        uVar11 = (uVar11 << 8 | pos3) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                        uVar11 = (uVar11 << 8 | pos4) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                        uVar11 = (uVar11 << 8 | pos5) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                        uVar11 = (uVar11 << 8 | pos6) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                        bytesRemaining = bytesRemaining - 1;
                    }
                    while (bytesRemaining != 0);
                }
            }
        }
        leftoverBytes = maxLength - bytesEvaluated;
        if(bytesEvaluated < maxLength) {
            do {
                bVar7 = param1.get();

                param1 = newAdjustedBuffer(param1, 1);

                uVar11 = (uVar11 << 8 | bVar7) ^ (seed + (uVar11 >>> 0x16 & 0x3fc));
                leftoverBytes = leftoverBytes - 1;
            }
            while (leftoverBytes != 0);
        }


        return ~uVar11;
    }

    private ByteBuffer newAdjustedBuffer(ByteBuffer prevBuffer, int amount) {
        byte[] remainingBytes = new byte[prevBuffer.limit() - 1];
        prevBuffer.get(remainingBytes, 1, remainingBytes.length);
        return ByteBuffer.wrap(remainingBytes);
    }
}